Stator construction for switches



y 1949- G. o. PUERNER 2,470,951

STATOH CONSTRUCTION FOR SWITCHES Filed NOV. 21, 1944 INVENTOR. f/mr F U, fiarlw r Mada 5 TTUIPNE) Patented May 24, 1949 UNITED STATES- EA TENT OFFICE STATOR CONSTRUCTION FOR SWITCHES George 0. Puerner,-Indianapolis,--Ind., assignor to I. E. Mallory & (10., Inc., Indianapolis, Ind, a corporation of Delaware Application November 21, 1944, Serial No. 564,440

is disclosed a rotary switch combining small size with the possibility of controlling a large number of circuits, making it well adapted for use as a short wave, tone control or tap switchinradiowork and for a multi-circuit control switch in many other applications. This switch essentially comprises a metal case having an insulative stator plate or disc mounted thereon and a rotatable shaft having an insulating rotor mounted thereon. The stator disc is provided with a plurality of individual contacts and with one or more common contacts, or grounding rings.

operate with the stator contacts to connect them in a predetermined variety of ways. The switch is also equipped with rotor indexing and stop means for indexing and limiting the rotation of the rotor assembly.

In many practical applications of rotary switches of the described general type, it is essential that two adjoiningindividual contacts of the stator disc be not connected directly with each other by means ofthe bridging contacts, while the bridging contact passes from one individual contact to the next one. In other words, for certain practical applications, the switch has to be of the non-shortingtype. This condition of operation has been heretofore assured by the provision of stamped-up bosses in the insulative stator disc, located in the interspaces between adjoining individual contacts. When the said bosses have been made slightly higher than the,

contacts at both sidesthereof, they would. lift up the bridging contact and wouldprevent its dropping into the interspace between the contacts and consequent shorting of such contacts. At the same time, they assured smooth gliding, of the bridging contact from one contact to the other, which was desirable from the point of view of smooth and silent operation. These bosses, integrally stamped up from relatively thin wafers of brittle insulating materials, such as for example Bakelite, were a frequent source of manufacturing and operating difficulties as they would be of a generally unequal height and also would frequently fall out from the wafers or stator discs.

It is an object of the present invention to eliminate the foregoing difficulties from the manufacture' of rotary non-shorting switches of the described general type.

It is another object of the invention to provide a stator construction for rotary switches in which the stator plate is provided with a ground ring of novel and improved character, having integral extensions protruding into the interspaces of the The rotor carries one or more bridging contacts adapted to individual contacts and thus preventing dropping of the rotatably displaced bridging contact into shorting position between said contacts.

Other and further objects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings; in which Fig. 1 is a top elevational view of a stator disc embodying the principles of the invention, with portions of the rotor and of the bridging contact thereon; and

Fig. 2 is a section, somewhat fragmentary in character, taken on line 22 of Fig. 1.

While a preferred embodiment of the invention is discribed herein, it is contemplated that considerable variation may be made in the method of procedure and the construction of parts without departing from the spirit of the invention. In the following description and in the claims, parts will be identified by specific means for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring now more particularly to the drawing, reference character Ill denotes the stator plate or disc, constituted of insulating material and having a plurality of individual contacts ll uniformly distributed over the circumferential surface thereof, the said contacts being integrally formed with soldering lugs 12 and extending away from the stator plate for the convenient connection of electrical conductors thereof. A spider member 14, stamped of a thin sheet of metal is also secured to the stator plate by means of eyelets l5, and comprises a ground ring H5 with integrally formed extensions or cars ll. One of suchears is provided for each of individual contacts H and is so arranged that it extends into the inter-space it? between. two contacts. Preferably, the thickness of the said spider plate 14 is so determined that the extensions or ears l1 have their exposed upper surfaces slightly higher than the upper surface of the contacts H.

To the rotary actuating shaft l9 of the switch there is secured an insulative rotor 26, parallelspacedwith respect to stator disc l0, and has a bridging contact 2! inserted therein. This rotor or bridging contact is stamped from a single piece, of resilient sheet metal so as to have a pair of rounded elongate contact surfaces 22 joined by a flat connection portion and having upwardly projecting side flanges 26 by means of which it is inserted into corresponding slots of the rotor member. The rotor contact is also provided with apair of leaf spring portions 25 whereby its contact surfaces are resiliently pressed against the stator disc. In view of the fact that the construction of the rotor contact and its cooperation with the rotor and stator disc forms no part of the present invention, it will not be necessary to describe all details thereof, particularly as such construction is fully disclosed in the said U. S. Patent 2,186,638 to which reference is hereby made.

From the foregoing description, the operation of the novel stator disc'of the invention will be readily understood by those skilled in the art. When shaft Ill is rotated, rotor contact member 2| will be step-by-step transfered into successive positions wherein the said contact member selectively connects individual contacts H with ground ring it. On the other hand, when the rotor contact member is transferred from one individual contact to the next one and arrives into the intermediate position between such contacts illustrated in the drawing, it will be prevented from dropping into the interspace l3 between adjoining contacts by one of extensions or ears ll of the spider-shaped ground ring. If desired, this extension may be also caused to lift the rotor contact member slightly upwards. In any case, shorting of two adjoining contacts during the contact-changing operation is positively prevented.

The principal advantages of the invention are that the extensions preventing shorting or adjoining individual contacts are integrally formed with the ground ring so that they may be provided at little or no extra cost. At the same time, the extensions being formed of metal, they are not appreciably subject to wear, or to warping and deformation, which are unavoidable with structures stamped out of the body of the stator disc, or in general with structures constituted of thin insulative material.

Although the present invention has been disclosed in connection with a preferred embodiment thereof, variations and modifications may be resorted to by those skilled in the art without departing from the principles of the invention. Thus, ground ring it, forming the common contact of the switch, may be split into two, three, or more segmentary portions, in order to provide a plurality of common contacts, as is necessary in multi-pole switches. Also, while the invention has been explained as applied to switches of the type disclosed in the said U. S. Patent 2,186,638, its principles may be applied with equal or similar results to all switches of the described general character. All of these variations and modifications are considered to be within the true spirit and scope of the present invention, as disclosed in the foregoing description and defined by the appended claims.

What is claimed is:

l. A rotary switch comprising in combination a stator plate, a plurality of individual contacts spacedly mounted on said plate at a uniform distance from each other and from the center of said plate, at least one common contact mounted on said plate, at least one bridging contact slidably displaceable with respect to said contacts adapted to selectively connect said individual contacts to said common contact, and extensions integrally formed with said common contact protradin into the interspaces between adjoining individual contacts to prevent the bridging contact from dropping into the said interspaces while passing from one individual contact to the next one.

2. A rotary switch of the non-shorting type comprising in combination an insulative stator disc, a plurality of contacts mounted on said disc in uniformly spaced circular arrangement, a metal spider member mounted in the center of said disc concentrically with respect to said contacts, said member having a continuous annular portion constituting a ground ring and integrally formed radial extensions spacedly protruding into each interspace between the said contacts, and a bridging contact slideable along circular paths over said contacts and said ground ring and adapted to selectively connect said contacts to the ring whereby said extensions of the spider member will positively prevent dropping down of the bridging contact between two successive contacts.

3. In a rotary switch of the non-shorting type having a stator disc with a set of spaced stationary contacts and at least one ground ring mounted thereon, and at least one rctatably dis placeable bridging contact for selectively connecting said stationary contacts to said rings; the improvement which comprises radial extensions integrally formed with said rings protruding into the interspaces between adjoining stationary contacts upon which the bridgin contacts may slide while passing from one contact to the next one thereby to prevent dropping of the bridging contacts into the interspaces and shorting of such adjoining contacts.

4. In a rotary switch of the non-shorting type having a stator disc with a set of spaced stationary contacts and a ground ring mounted thereon, and a rotatably displaceable bridging contact for selectively connecting said stationary contacts to said ring; the improvement which comprises radial extensions integrally formed with said ring protruding into the interspaces between adjoining stationary contacts upon which the bridging contact may slide While passing from one contact to the next one, the upper surface of said extensions being slightly higher than that of the set of stationary contacts whereby shorting of such adjoining contacts is prevented.

5. A rotary switch comprising, in combination, a stator plate, a plurality of individual contacts spacedly mounted on said plate at a uniform distance from each other and from the center of said plate, a rotary member having a contact mounted thereon which is adapted to selectively engage said individual contacts, and a spider member secured to said plate, said spider member including extensions integrally formed therewith and protruding into the interspaces between adjoining individual contacts to pre cut the rotary contact from dropping into said interspaces when passing from one individual contact to the next one.

GEORGE O. PUERNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 394,220 Sparrow I Dec. 11, 1888 FOREIGN PATENTS Number Country Date 15,566 Great Britain Nov. 20, 1913 

